#!/bin/bash
# use ffmpeg to do video format conversion
# $1 is file name
# $2 is the stream index in subtitles
# $3 is the output file name.
ffmpeg -i $1\
    -vf scale=-1:360,subtitles=$1:si=$2 \
    -b:v 0.96M \
    -c:v libx264 \
    $3

